A convenient source of radionuclides used in biomedical applications is often a radionuclide generator. In such a system an efficient radionuclide separation is used to periodically isolate a short-lived parent. The stringent requirements imposed on such systems, especially for nuclear medicine applications, have limited the number of radionuclide generators that have ben successfully developed and made commercially available for routine use. The development of a new radionuclide generator, based on 118Te/118Sb, is the main objective of this research project. The 3.5-min 118Sb daughter decays principally by positron emission, and has a potential use in first- pass angiography. Column chromatography procedures will be developed to achieve the necessary separation of the 118Sb from the 118Te parent. Activated carbon, along with other commercially available adsorbents, and in combination with a variety of mobile phases, will be systematically evaluated for conditions of optimal 118Sb elution and minimal 118Te breakthrough. The stability and reproducibility of the experimentally determined optimal generator conditions will also be evaluated. The 118Te parent will be produced by proton bombardment of antimony targets, and radiochemically separated using existing procedures. A careful measurement of Sb(p,x) cross sections in the proton energy range of 28-46 MeV will be made using stacked foil and activation techniques. This cross section information will permit optimization of parent production in thick targets, as well as serve as a test of models used to calculate excitation functions.